Meaning and history
Probably from Old Irish cell meaning “church,” combined with a diminutive suffix, this name belonged to a 7th-century Irish saint who evangelized in Franconia and was martyred in Würzburg.
20062006: 42 births, rank #2,744
2007: 39 births, rank #2,974
2008: 51 births, rank #2,467
2009: 52 births, rank #2,451
2010: 54 births, rank #2,354
20112011: 66 births, rank #2,035
2012: 73 births, rank #1,942
2013: 77 births, rank #1,851
2014: 87 births, rank #1,730
2015: 121 births, rank #1,416
20162016: 177 births, rank #1,105
2017: 170 births, rank #1,126
2018: 193 births, rank #1,052
2019: 186 births, rank #1,078
2020: 228 births, rank #957
20212021: 341 births, rank #747
2022: 353 births, rank #735
2023: 477 births, rank #594
2024: 668 births, rank #463
20252025: 595 births, rank #507
Cillian moved from #463 to #507 for boys between 2024 and 2025. Its highest annual birth count came in 2024, with 668 births.